Influence of sumac sorghum bran inclusion and extrusion conditions on physicochemical and antioxidant properties of expanded snacks

Authors: Scott Sr, Ronson; Olson, Douglas; Boue, Stephen; Smith, Brennan

Submitted to: Journal of Food Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/22/2025
Publication Date: 1/11/2026
Citation: Scott Sr, R.R., Olson, D.W., Boue, S.M., Smith, B. 2026. Influence of sumac sorghum bran inclusion and extrusion conditions on physicochemical and antioxidant properties of expanded snacks. Journal of Food Science. https://doi.org/10.1111/1750-3841.70840.
DOI: https://doi.org/10.1111/1750-3841.70840

Interpretive Summary: The study evaluated how incorporating sumac sorghum bran into corn-based extruded snacks influences product quality and antioxidant properties. A response surface design tested bran inclusion level, extruder screw speed, and feed rate for their effects on expansion, phenolic content, tannin levels, and antioxidant capacity (ORAC), along with texture and color. Results showed that increasing bran raised antioxidant measures (total phenolics and ORAC) but reduced expansion and increased density. Tannin levels rose sharply when bran exceeded 16%. Screw speed and feed influenced energy input and texture but had little effect on antioxidant measures. Optimization identified 20% bran, moderate screw speed, and moderate feed rate as the best combination, producing snacks with enhanced phenolic content and antioxidant capacity while maintaining acceptable physical quality. These findings highlight the potential for tannin-rich sorghum bran to create antioxidant-enriched snack products. More broadly, this research demonstrates how cereal brans can be used to enhance the nutritional quality of extruded foods, providing insights that extend into rice and other staple grains in efforts to increase their value, functionality, and contribution to human health.

Technical Abstract: The incorporation of sumac sorghum bran into corn-based extruded snacks was evaluated for its impact on physical properties and antioxidant capacity. A three-factor response surface methodology (RSM) was used to assess the effects of bran level (0–30%), screw speed (150–300 rpm), and feed rate (9–25 kg/h) on expansion ratio, total phenolic content (TPC), oxygen radical absorbance capacity (ORAC), and tannin content, alongside secondary responses including hardness, color, and crispness. Increasing bran inclusion significantly enhanced TPC and ORAC but reduced expansion and increased product density. Screw speed and feed rate influenced specific mechanical energy (SME), hardness, and phenolic release, with minimal effects on ORAC and water absorption index (WAI). Tannin content followed a quadratic trend with respect to bran level, increasing sharply beyond 16% inclusion. Optimization using desirability functions identified 20% bran, 184 rpm screw speed, and 21.76 kg/h feed rate as the most favorable conditions, yielding an expansion ratio of 3.25 mm, TPC of 4832 µg GAE/g, ORAC of 165 µmol TE/g, and moderate tannin content (1067 µg/g). These findings support the use of tannin-rich sorghum bran to produce antioxidant-rich extruded snacks while maintaining acceptable product quality.